LED lamp assembly

ABSTRACT

A lamp finding particular application in boat trailers and other vehicular applications is provided with a generally unbreakable lens structure. The lamp preferably is provided with a plurality of LEDS arranged with rows and columns on a circuit card or board. The lamp is constructed by encapsulating the board and LED arrangement in a moldable lens material, which after removal from a suitable mold at least partially defines the lamp housing.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional application of U.S. patentapplication Ser. No. 09/521,808 filed Mar. 9, 2000 now U.S. Pat. No.6,739,733, the contents of which are expressly incorporated herein byreference.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

BACKGROUND OF THE INVENTION

This invention relates generally to lamps, and more specifically tovehicle lamps having an array of light emitting-diodes (LEDS) providingthe light, and a structure and method of construction which produces alight structure which is relatively unbreakable and water resistantand/or water proof. While the invention is described in particular withits application in and to boat or other similar towed trailers, thoseskilled in the art will recognize the wider applicability of theinventive principles disclosed hereinafter.

One of the problems we have observed with respect to taillights ofvarious boat trailers and other towed trailers for example, and withrespect to vehicle lights in general, is the fact that the lights oftenbecome damaged. That is, it is not uncommon for a person who does notroutinely tow a boat trailer, to experience problems in backing the boattrailer, for example. Often in backing, the taillight of the trailerbecomes damaged. Likewise, boat trailers often are backed into water inorder to load or unload a boat to be carried or carried by the trailer.Because prior art light assemblies are not waterproof, water enteringthe light assembly can and often does damage the electrical capabilitiesof the light. We have developed a relatively low-cost, waterproof/resistant and relatively unbreakable back up and/or taillightand/or turning light, for example, that has wide application forvehicles, both driven and towed. In particular, we have found that alight can be molded completely from a suitable copolymer, poly-carbonateor acrylic plastic, and inserted in place of conventional taillights ontrailers and vehicles, for example. Preferably, we employ light emittingdiodes (LEDS) as the source of illumination for the light structure. TheLEDS are mounted to a circuit card or board in any predeterminedarrangement. The board and associated LEDS then are completelyencapsulated during the manufacturing process.

While other lamp assemblies have employed LEDS in the past, the productsof which we are aware did not provide a light structure which isrelatively unbreakable alone or water proof/resistance in combinationwith the structure's other features. For purposes of this specification,relatively unbreakable means unbreakable in the environment of the lampassembly's intended use during expected or normal operating conditions.For example, we have found that Spector Copolymer available from EastmanChemical Company is an acceptable material for the lamp assembly of thepresent invention where the light assembly is intended for use in boattrailers. That material, in “sheet form,” has an impact resistance at32° F. of 93 lbs. per sq. inch (6 mm thick material) and 71 lbs. per sq.inch at 73° F. In boat trailer applications, the material thickness mayapproach one inch or more, for example, a thickness for which we wereunable to find manufactures data. We have tested other poly-carbonatematerial in prototype assemblies that has sustained 30 ft. lbs. force onthe light assembly without damage (tested by dropping a five poundweight from a height of six feet). As indicated above, the preferredmaterial for any particular application is one that does not sufferdamage in it intended application during normal or intended operation ofthat application.

Among the devices of which we are aware which employ LEDS is onedescribed in U.S. Pat. No. 5,632,551 ('551). While employing LEDSgenerically, the '551 patent describes the use of a conventional lensand an associated metal housing. While recognizing that breakage is aproblem, the '551 patent attempts to solve that problem by recessing thelens member within the housing. While the invention described in the'551 may function well in some circumstances, it does not provide thesimplified structure, water proof/resistance construction and true nonbreakable design for light assemblies available with our invention.

BRIEF SUMMARY OF THE INVENTION

One of the objects of this invention is to provide a low-cost lampassembly;

Another of object of this invention is to provide a lamp assembly whichis relatively unbreakable in applicational use.

Another object of this invention is to provide a lamp or light structureemploying LEDS for the light source.

Another object of this invention is to provide an LED lamp structure inwhich the LEDS are arranged in rows and columns, the arrangement ofwhich permits LEDS emitting various visible light colors to be employedin the light structure.

Yet another object of this invention is to provide a lamp structurewhich is directly replaceable with existing applications for similarlamps assemblies.

Another object of this invention is to provide a lamp structure whichexhibits at least water resistance capabilities for preventing damage toelectrical components of the structure.

Other objects will be apparent to those skilled in the art in light ofthe following description and accompanying drawings.

In accordance with this invention, generally stated, an unbreakable lampfinding particular application in automotive vehicle and trailers, forexample is provided in which the lamp housing defines the lens and thehousing itself. Preferably, the lens is constructed from an unbreakablematerial, unbreakable being defined herein. The lamp includes a circuitboard or card having a light unit associated with it. In the preferredembodiment, the light unit is a plurality of LEDS arranged in rows andcolumns. The light unit and the circuit board are encapsulated by thelens material. Encapsulation provides at least water resistanceproperties to the lamp assembly. The lens material is molded in apredetermined manner to provide the housing for the lamp assembly.

A method of constructing a lamp assembly in which the lens materialdefines a lamp housing also is disclosed.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The objects of the invention are achieved as set forth in theillustrative embodiments shown in the drawings, which form a part of thespecification. In the drawings,

FIG. 1 is view in perspective, partly broken away, of one illustrativeembodiment of lamp assembly of the present invention;

FIG. 2 is a sectional view taken along the line 2—2 of FIG. 1;

FIG. 3 is a rear plan view of the lamp assembly shown in FIG. 1; and

FIG. 4 is a block diagram of one illustrative method shown manufacturingthe lamp assembly shown in FIGS. 1 through 3.

Corresponding reference characters indicate corresponding partsthroughout the several views of the drawings.

DETAILED DESCRIPTION OF INVENTION

The following detailed description illustrates the invention by way ofexample and not by way of limitation. This description will clearlyenable one skilled in the art to make and use the invention, anddescribes several embodiments, adaptations, variations, alternatives anduses of the invention, including what we presently believe is the bestmode for carrying out the invention. It will nevertheless be understoodthat no limitation in the scope of the invention is thereby intended,and that alterations and further modifications of the illustrativedevices are contemplated, including but not limited to such furtherapplications of the principles of the invention illustrated herein aswould normally occur to one skilled in the art to which this inventionrelates.

Referring now to FIG. 1, reference numeral 1 indicates one illustrativeembodiment of lamp assembly of the present invention. The lamp assembly1 includes a housing 4, which surrounds a circuit board or card 6, anelectrical connection 8, and a light source 10 a, preferably a pluralityof LED lamps 10.

The circuit board 6 is conventional and is not described in detail.Circuit boards or cards used to hold various electrical components arewell know in the art. In the embodiment illustrated, the card or board 6has a plurality of LED lamps 10 mounted to it. The LEDS preferably arearranged in rows 12 and columns 14, as best seen in FIG. 1. Mounting orattachment of the LEDS to the board 6 likewise is conventional and isnot described in detail. Regardless of the attachment method, variousarrangements of the LEDS are compatible with the broader aspects of theinvention, and depend to some measure on the shape of the housing 4and/or the intended use of the lamp assembly. For example, although agenerally rectangular enclosure 4 as shown in the drawings, thoseskilled in the art will appreciate that other shapes, including round,elliptical, triangular, emblematic and the like may be employed in otherembodiments of the invention. The configuration of the enclosure 4 willoften determine the arrangement required or permitted the LEDS. Thoseskilled in the art also will recognize that the LEDS need not bearranged in rows and columns, in that a single LED may be employed inother applications of the invention.

The LEDS 10, as indicated, are mounted to the circuit board 6 in aconventional manner. The electrical connection 8 also is mounted to thecircuit board 6 in a conventional manner, permitting the lamp assembly 1to be inserted as a replacement for a more conventional taillight notshown, for example, of a boat trailer or a similar application.Connection 8 includes a pair of snap-in arms 16, and three power leads,17, 18 and 19 respectively. The leads permit the LEDS to be operated ina number of ways, later described in greater detail. In the preferredembodiment, the electrical connection 8 is preassembled to the circuitboard, and the electrical connections to the LEDS are made through thecircuit board construction. In the alternative, individual electricalleads, not shown, may be brought out from the housing 4 forinterconnection to a power source, likewise not shown. While a maleconnection is illustrated in FIG. 2, those skilled in the art willappreciate that a female or other interconnection form may be employed,if desired.

Our design is unique, for example, because the housing 4 also definesthe lens and the body for the lamp assembly 1. Preferably, the housing 4is constructed from relatively unbreakable material. Spector Copolymeravailable from Eastman Chemical Company is an acceptable material forthe lamp assembly of the present invention where the light assembly isintended for use in boat trailers. As indicated above, that material, insheet form, has an impact resistance at 32° F. of 93 lbs. per sq. inch(6 mm thick material) and 71 lbs. per sq. inch at 73° F. In boat trailerapplications, the material thickness may approach one inch or more, forexample, a thickness for which we were unable to find manufactures data.We have tested other poly-carbonate material in prototype assembliesthat has sustained 30 ft. lbs. force on the light assembly withoutdamage (tested by dropping a five pound weight from a height of sixfeet). Again, the preferred material for any particular application isone that does not suffer damage in its intended application duringnormal or intended operation of that application. In the context of thisspecification and invention, “unbreakable” has this meaning ascribed toit. The Spectar Copolymer material initially is flowable, and sets up toa final shape over some predetermined period of cure time. The method ofcure may vary, depending on the material used to form the housing 4. Forexample, some material may cure in a satisfactory time merely with anambient air cure. Other materials may require the application of heat tocure satisfactorily. Regardless of cure, however, all embodiments of theinvention are designed so that the housing 4 encapsulates at least theLEDS 10 and circuit board 6, and arranged and formed to define the lensassembly for the lamp 1. That encapsulation, in turn, provides at leastwater resistance properties to the lamp assembly 1, since the materialis impervious to liquid. If care is taken in the manufacturing processwith the electrical connection to the circuit board 6, the lamp assembly1 easily can be made to be water proof in the conventional sense of thatterm.

A preferred method of manufacture is shown in FIG. 4. A suitable mold 40is constructed in a conventional method. The mold 40 is designed so thatlamp assembly 1 has its intended shape upon removal from the mold. Thatis to say, the mold 40 is preformed so that the finished lamp assembly 1may be extracted from the mold directly.

The LEDS are mounted to the circuit board 6 in a step 42. That combinedassembly then is placed in the mold 40 in a step 44. As indicated above,preferably the electrical connection 8 is attached to the circuit boardand inserted in the mold simultaneously with the circuit board and LEDS.However, the electrical connection may be made at a later time, ifdesired.

In the embodiment illustrated, the mold 40 also has provisions forproviding one or more openings 36 through the enclosure. Alternatively,the openings 36 may be formed in the assembly 1 after removal from themold. Those skilled in the art will recognize that the openings 36 maybe eliminated in other embodiments of the invention. In any event, afterplacement of at least the LEDS and circuit board in the mold 40, themold is filled with lens material to encapsulate the LEDS and circuitboard completely, as illustratively shown in FIG. 2. Thereafter, thelens material is cured in a step 48 and the essentially finished productis removed from the mold in a step 50.

Because of the ease of manufacture, those skilled in the art willrecognize that a number of attributes can be obtained with the lampassembly 1 of the present invention. Merely by way of example, one ormore of the rows 12 of the LEDS 10 may emit a different light spectrumfrom the remainder of the LEDS. Thus, certain of the LEDS may bearranged to provide a yellow arrow indicating a turning motion for thevehicle, while the remaining LEDS emit a light from the red spectrumindicating when the vehicle brakes are applied, for example. Likewise,the material forming the housing 4 may have a color pigment associatedwith it so that the enclosure 1 has a familiar red brake lightconfiguration, if desired.

In view of the above, it will be seen that the several objects of theinvention are achieved another advantageous results are obtained. Asvarious changes could be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense. Numerous variations, within the scope of the appended claims,will be apparent to those skilled in the art in light of the foregoingdescription and accompanying drawings. For example, as indicated, theenclosure 1 may assume a variety of shapes. Other materials may beemployed for the enclosure besides that described. The LED arrangementmay vary in other embodiments of this invention. Likewise, the enclosuremay be formed in a lens design, if desired. While the light assembly 1is described as utilizing LEDS, other forms light emitting structuresmay be employed, if desired. Thus, conventional incandescent lamps ordifferent unconventional sources of light may be employed in embodimentsof the invention. LEDS presently are preferred because they offer lowenergy consumption and long life in applicational use. The lightassembly 1 also may be attached to a second structure in a number ofways. Merely by way of example, while conventional threaded fastenersthrough suitable openings work well, the light assembly 1 may be bracketmounted, surface mounted, or recessed mounted in a friction fit, ifdesired. Applications of the light assembly 1 are numerous, and thedescription with respect to boat trailers is not to be construed in alimiting sense.

In view of the above, it will be seen that the several objects andadvantages of the present invention have been achieved and otheradvantageous results have been obtained.

1. A method for forming a lamp assembly, comprising: providing a mold having a predetermined shape corresponding to the desired shape of said lamp assembly; positioning a circuit board having a plurality of light emitting diodes (“LEDs”) mounted thereto in said mold; filling the mold with a flowable lens material to immerse the LEDs within the material and such that the flowable lens material itself forms the exterior of the lamp assembly; hardening the lens material such that the flowable material forming the exterior of the lamp assembly provides a rigid exterior of the lamp assembly; and removing the lamp assembly from the mold; reusing said mold for molding subsequent lamp assemblies.
 2. The method of claim 1 further including the steps of adding a color pigment to the lens material.
 3. The method of claim 2 further including the step of attaching an electrical connection to the light emitting diodes.
 4. The method of claim 3 further including the step of placing the electrical connection in said mold.
 5. The method of claim 4 wherein said LEDs are arranged in rows and columns.
 6. The method of claim 5 wherein at least one LED emits a light color different from the other LEDs.
 7. A method for forming a lamp assembly comprising: providing a mold having a shape corresponding to the desired shape of said lamp assembly; positioning a circuit board having a plurality of light emitting diodes (“LEDs”) mounted thereto in said mold; filling the mold with a flowable lens material to immerse the LEDs and the circuit board within the material and such that the flowable lens material itself forms the exterior of the lamp assembly; hardening the lens material such that the flowable material forming the exterior of the lamp assembly provides a rigid exterior of the lamp assembly; and reusing said mold for molding subsequent lamp assemblies.
 8. The method of claim 7 further including the steps of adding a color pigment to the lens material.
 9. The method of claim 8 further including the step of attaching an electrical connection to the light emitting diodes.
 10. The method of claim 9 further including the step of placing the electrical connection in said mold.
 11. The method of claim 10 wherein said LEDs are arranged in rows and columns.
 12. The method of claim 11 wherein at least one LED emits a light color different from the other LEDs.
 13. A method for forming a lamp assembly comprising: providing a mold corresponding to the desired shape of said lamp assembly; positioning a plurality of light emitting diodes (“LEDs”) in said mold; interconnecting the LEDs to an electrical lead; filling the mold with a flowable lens material to immerse the LEDs within the material and such that the flowable lens material itself forms the exterior of the lamp assembly; hardening the lens material such that the flowable material forming the exterior of the lamp assembly provides a rigid exterior of the lamp assembly; and reusing said mold for molding subsequent lamp assemblies.
 14. The method of claim 13 further including the steps of adding a color pigment to the lens material.
 15. The method of claim 14 further including the step of attaching an electrical connection to the light emitting diodes.
 16. The method of claim 15 further including the step of placing the electrical connection in said mold.
 17. The method of claim 16 wherein said LEDs are arranged in rows and columns.
 18. The method of claim 17 wherein at least one LED emits a light color different from the other LEDs. 